To repair a crack in concrete, simply clean the crack by removing excess pieces, and dust with both a chisel and a broom before applying patching compound to the area. You need a cold chisel, a hammer, a concrete trowel or putty knife, concrete patching compound, a broom, water-based polyurethane and a paint roller.
- Chisel away excess concrete
Place the blade of the chisel against an excess piece of concrete within the crack, and hit the other end of the chisel with a hammer to chip away the piece. Repeat until the crack is clean of excess concrete.
- Clean the crack
Use a broom to sweep away excess dust and smaller pieces of concrete. Vacuum and wash the crack if it is particularly dirty.
- Apply the concrete patching compound
Mix the concrete patching compound as is recommended by the manufacturer. Use the trowel to tap around the side of the patching compound bucket to remove air pockets. Scoop up an adequate amount of the compound with the trowel, and use the trowel to spread the compound over the crack. Repeat until the crack is filled and appears smooth. Allow the compound to dry for as long as the manufacturer recommends, or overnight.
- Seal the patch
Apply a water-based polyurethane with a paint roller to seal the patch.